Hydraulic lifting mechanism.



F. KOENIGKRAMER. HYDRAULIC LIFT |NG MECHANISM. APPLICATION FILED OCT. 25. 1913.

Patented Dec. 14, 1915.

2 SHEETS-SHEET 1. I H70 F. KOENIGKRAMER.

HYDRAULIC 11mm; MECHANISM. APPLICATION.F|LED OCT. 25. 1913.

MW LWU. Patented Dec. 14, 1915.

2 SHEETS-SHEETQ.

I TAT t FRANK KOENIG-KRAMER, 0F CINCINNATI, OHIO, ASSIGNOR 0F ONE-HALF 'IO FREDERICK KOENIG-KRAMER, 0F CINCINNATI, OHIO.

HYDRAULIC LIF'I'ING MECHANISM.

Application filed October 25, 1913. Serial No. 797,323.

To all whom it may concern."

Be it known that I, FRANK KohNIo- KRAMER, citizen of the United States, residing at Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Hydraulic Lifting Mechanism, of which the following is a specification.

My invention relates to hydraulic mechanism for operating chairs and tables for barber, dental, and surgical purposes. One of its objects is to provide improved and simple liquid pumping mechanism and releasing mechanism.

Another object is to provide improved and reliable brake or locking mechanism capable of being operated with a minimum of strain or vibration.

Another object is to provide improved mechanism to lock and release the reclining mechanism with a minimum of strain or vibration.

Another object is to provide for carrying out the several operations with a single im: proved lever mechanism.

My invention also comprises certain details of form, combination, and arrangement, all of which will be fully set forth in the description of the accompanying draw-- ings, in which:

Figure 1 is a central vertical section on line '12 q; of Fig. 3, of my improved mechanism. Fig. 2 is a central vertical section through the same at right angles to Fig. 1, on line a a of Fig. 3. Fig. 3 is a top plan view upon an enlarged scale. Fig. A is a perspective View of the crank pin and cam member carried at the inner end of the actuating lever. Fig. 5 is a bottom plan view of the hydraulic plunger. Fig. '6 is a bottom plan view of the pump piston. Fig. 7 is a sectional detail of the lower end of the plunger and piston in position to release the liquid. Fig. 8 is a similar view showing the plunger and piston in a difl'erent osition. Fig. 9 is a perspective view 0 the brake or looking member detached. Fig. 10 is a perspective viewv of the member employed to lock and release the reclining bar, detached. Fig. 11 is. a sectional detail through the plunger similar to Fig. 2, and illustrating a modification.

The accompanying drawings represent the preferred embodiment of my invention, in which A represents the cylinder and B the plunger ofa hydraulic lifting mechanism. the cylinder being usually mounted upon a base or standard, and the plunger attached to the body of a chair or table to be lifted and lowered or reclined by said mechanism. At the lower end of the plunger is a detachable head 2 provided with a port 3 and a valve 4 held in place by a flat spring 5 held by a screw 6 to the under face of said head. An upwardly projecting post 7 having an annularly reduced portion or neck 8 is carried by the head 2. Mounted Within the cylindrical bore of the plunger 18 is a piston head D which is connected by a wrist pin 9 with a pitman 10 to reciprocate said piston head within the plunger. Said piston head is preferably of the cup-shaped type with a section of the side wall cut away at 4:5 to admit the brake or looking member Fig. 9. Said piston head is provided with a port closed by a valve 11 held in place by a spring 12 fastened by a screw 14: to the face of the piston head. A screw 15 is also tapped into said piston head in line with the port 3 and valve 4, and is adjustable so as to engage and open the valve 4 at a predetermined po' sition of the piston head. Ihe pitman 16 is preferably of yoke shape at its lower end and a roller 16 is mounted upon the wrist pin between the forks of said pitman. A recess 17 through the center of the piston head permits the passage of the post 7 the greater circumference of said post being closely fitted by said recess. The vertical dimension of said recess is practically the same as the vertical dimension of the head section of the post 7, and slightly less than the vertical dimension of the port or neck portion of said post.

An operating lever E is journaled m a bearing in one side of the upper portion of the plunger B, and the outer upwardly turned end of said lever is provided with a handle. To the inner end of said lever is firmly secured by set screws 18 a head or collar 19 which carries a crank pin 20 to which the upper end of the pitman 10 is journaled. Said head also carries a cam or the piston head comes tooth 21 to engage the upper end of a bar 22 r to shift said bar endwise. Another cam 24 carried by the head 19 engages a roller 25 to release a reclining bar and permit the chair or table top to be inclined at an angle.

The reclining bar 26 is seated at the upper end of the plunger in 'site sides of said. plunger. Said bar' also passes through perforations 27 in opposite ends of a yoke shaped lever 28 which is pivotally supported with reference to the plunger by rod 29. -The opposite or free end of the lever 28 has journaled thereto the roller 25 in the path of the cam 24 by means of which the lever 28 may be depressed. Coiled springs 30 are interposed between the lever 28 and the face of the plunger, and held against displacement by lugs projecting downwardly into said springs from the lever 28, said springs tending to elevate the free end of lever 28, and thereby to frictionally lock the reclining bar against endwise displacement where it passes through the perorations in the plunger and the perforations in the lever 28. It will be noted that by passing the reclining bar through perforations in both the plunger and lever 28, said lever will have a double locking action, due to forcing the perforations through which said reclining bar passes out of alinement either upwardly or downwardly, and hence either the cam or the spring pressure may be utilized to retain the reclining bar in its adjusted position. By passing the reclining bar through closely fitting perforations in both the plunger andlever 28, a firm locking action is obtained with a minimum of wear'on the locking members and a minimum action to release the bar. The engagement of the cam 24 with the roller 25 to release the reclinin bar can also be effected with practically no friction and consequently wilthout strain or vibration of the chair or ta e.

The throw of the lever E enables the piston head D to assume several different ositions with reference to the post 7, as ustrated in Figs. 1, 2, 7, and 8, and also a pumping position intermediate of that shown in Figs. 2 and 7. Thus in substantially the position illustrated in Figs. 1 and 2 the crank pin 20 is on dead center, and the piston head is held practically stationarily with reference to the plunger, also the recess 17 is above and out of engagement with the post 7, forming a port for the free assage of fluid through the iston head. 11 this position the valve 4 is c osed and resists the tendency of liquid to esca e -u wardly from below the plunger. Es t e crank pin 20 approaches a dead center and to rest at the upward limit of its stroke, the cam 21 engages a notch or recess 32 in the upper end of bar 22 and quickly thrusts said bar endwise perforations in oppodownwardly. The lower end of the bar 22 rides in a channel shaped groove 33 in the rear face of a brake shoe 34 which is seated in a recess in the side wall of the plunger B in position to frictionally engage the inner face of the cylinder A to lock the'plunger and cylinder firmly together. The lower end of the bar 22 is wedge shaped and when thrust downwardly engages between the grooved portion of the brake shoe and the roller 16 of the piston head, forcing the stationary piston head against one si e or face of the inner wall of the plunger and forcing the brake shoe in the opposite direction through the perforation in the plunger against the inner Wall of the cylinder. The action between the wedge and the roller are such as to enable this locking operation to be effected with practically no strain or vibration imparted to the chair or table, and with the piston head at rest in the plunger. A movement of lever E in the reverse direction causes the cam 21 to engage the upper projection 35 of bar 22 to lift said bar. A bolt 36 passing through a slot 37 in the plunger wall and threaded into the bar 22 serves in connection with a coiled spring 38 on said bolt to yieldingly hold said bar in position. The engagement of the bar 22 in the channel shaped recess of the brake shoe holds the brake shoe in position and in alinement with the cylinder wall. As the lever E, Fig. 2, is moved toward the right, and while the recess 17 is still out of engagement with the upper end of post 7, the cam 24 engages the roller 25 to depress the lever 28 to release and permit readjustment of tho reclining bar 26. Further movement of the lever E to the right, Fig. 2, disengages cam 24 and roller 25 relocking the reclining bar, and brings the recess 17 into engagement with the upper enlarged portion of post 7, closing recess 17 and cutting off a flow of liquid through said recess. In this position an oscillating movement of the lever E causes liquid to be pumped or forced downwardly through the valves 11 and 4, thus f rcing the plunger to a higher position in the cylinder. The limits of this oscillating movement of lever E are indicated approximately by the dotted lines 40 and 41. Further movement of lever E to the right, Fig. 2, shifts the piston head to the position illustrated in Fig. 7 with the recess 17 o posiie the neck or port 8 of post 7, and with the valve 4 held in open position by the screw 15. In this position liquid is enabled to flow vin considerable volume through the valve 4 portion of post 7 entirely closes and cuts off raeaaeo a flow of liquid through recess 17, and locks the plunger without vibration against further descent, the valve 4: remaining open.

In the modification Fig. 11 I have illustrated a tapered or inclined face 42 carried by the piston head between the forked arms of the pitman, and a roller 16 carried by the lower end of the bar 22 corresponding to the bar 22 of Fig. 2, to engage with and'ride upon said inclined face to force the brake shoe into engagement with the inner Wall of the cylinder to lock the plunger thereto. In like manner if desired the roller 25 and cam 24 may be transposed in position to that illustrated in Fig. 2.

As the patient or occupant of the chair or table is particularly sensitive to strains or vibrations imparted to the chair or table in operating the same, it is important to reduce such strains and vibrations to a minimum, which is effected in all the movements of my improved mechanism. Also the several different operative positions of the piston head enable the desired movements to be advantageously effected with a single operating lever, and the plunger locked while said head is in idle stationary position.

The mechanism herein illustrated and described is capable of considerable modification without departing from the principle of my invention.

Having described my invention, what I claim is:

1. A hydraulic lifting mechanism comprising a cylinder, a hollow plunger seated therein and provided with a valved port leading from the interior of said plunger to the cylinder beneath said plunger, a post carried rigidly by said plunger and projecting upwardly into the interior of said plunger from the bottom thereof wlth a fluid port intermediate of its ends, a piston head to reciprocate within said plunger and provided with a valved port leading downwardly therethrough and a through recess to receive and closely fit said post, an op crating lever journaled at the upper end to said plunger, and a pitman connecting said piston head to said operating lever to reciprocate said piston head.

2. A hydraulic lifting mechanism comprising a cylinder, a hollow plunger seated therein and provided with a valved port leading from the interior of said plunger to the cylinder beneath said plunger, a post carried rigidly by said plunger and proJeCtlllll mg upwardly into the interior of said plunger and provided with a fluid port intermediate of its ends, a piston head to reciprocate within said plunger, means carried by said plunger to reciprocate said piston head, said piston head being provided with a valved port leading downwardly therethrough, a through recess to receive and closely fit said post and means to openthe valve controlling said plunger port at a predetermined position of said piston head.

3. A hydraulic lifting mechanism comprising a cylinder, a hollow plunger seated therein and provided with a valved port leading from the interior of said plunger to said cylinder beneath said plunger, a piston head to reciprocate within said plunger and provided with a valved port leading downwardly therethrough, an operating lever journaled to said plunger and provided with acrank pin, and a cam, a pitman connecting said piston head to said crank pin, a brake shoe seated in a recess through the side wall of said plunger opposite the upper limit of the movement of said piston head to bear upon the inner Wall of said cylinder, a bar having sliding engagement with said brake shoe and adjustable endwise by said cam, said bar and piston head being provided with an inclined face and a roller to wedge said bar between said piston head and brake shoe to lock said cylinder and plunger tosaid cylinder beneath said plunger, a piston head to reclprocate within said plunger and provided with a valved port leading down- Wardly therethrough, an operating lever j ournaled to said plunger and provided with a cam, a pitman connecting said piston head to said operating lever, a brake shoe seated in a recess through the side wall of said plunger opposite the upper limit of the movement of said piston head to bear upon the inner Wall of said cylinder, a bar having sliding engagement with said brake shoe and adjustable endwise by said cam and having an inclined face, and a roller carried by said piston head to engage said inclined face to wedge said bar between said piston gird brake shoe to lock and release said brake 5. A hydraulic lifting mechanism comprising a cylinder, a hollow plunger seated therein, a piston head to reciprocate within said plunger, an operating lever journaled to said plunger and connected by apitman with said piston head, a brake shoe to engage the inner wall of said cylinder through a recess in the plunger wall, and means interposed between said brake shoe and said piston-head when stationary at the limit of its upward stroke and operably connected to said operating lever to force said brake shoe and piston head apart to lock said cylinder and plunger together.

6. A hydraulic lifting mechanism comprising a cylinder, a hollow plunger seated therein and provided with a valved port leading from the interior of said plunger to said cylinder below said plunger, a post pro-' jecting upwardly within said plunger from its bottom, a piston head to reciprocate within said plunger and provided with a valved port leading downwardly therethrough, a through recess to receive said post and a stud to open the valve of said plunger port,

and means to reciprocate said piston head leading from the interior of said plunger tosaid cylinder below said plunger, a piston head to reciprocate within said plunger.

and provided with a valved port leading downwardly therethrough, a downwardly projecting stud to open the valve of said plunger port, and a vertical through recess, a post projecting upwardly within said plunger from its bottom to engage said through recess through a portion of the piston head stroke, said post being provided with a port in its middle section, a brake shoe seated in a recess through the plunger wall at the upper limit of movement ofsaid piston head, an operative lever to reciprocate said piston head, and means interposed between said piston head and brake shoe to lock said brake shoe to the inner wall of said cylinder.

8. A hydraulic lifting mechanism comprising a cylinder, a hollow plunger seated therein and provided with a valved port leading from the interior of said plunger to said cylinder below said plunger, a piston' head to reciprocate within said plunger, a brake sh'oe seated in a recess through the side wall of said plunger at the upper limit of the piston head stroke, an operating lever provided with a cam and connected by a pitman to said iston head, a roller journaled upon the wrlst pin of said piston head and a wedge shaped bar operated by said cam and engaging said roller and brake shoe to releasably lock said cylinder, plunger, piston head and brake shoe together when said piston head has reached a stationary position at the limit of its stroke.

In testimony whereof I have afiixed my signature in presence of two witnesses. FRANK KOENIGKRAMER.

Witnesses:

C. WV. MILEs, W. THORNTON Boonn'r. 

